The invention relates to a bearing arrangement comprising a shaft, an auxiliary member and a housing, which shaft is secured to the auxiliary member, the shaft being radially supported and the auxiliary member being axially supported in the housing.
The invention also relates to a rotatable-disc device comprising two parts which are rotatable relative to one another, one part being constituted by a stationary chassis and the other part being constituted by a rotatable hub carrying the disc, one of said parts comprising a shaft and the other part comprising a housing, which shaft is secured to the auxiliary member, the shaft being radially supported and the auxiliary member being axially supported in the housing.
The invention further relates to a magnetic-tape apparatus comprising a stationary drum and a rotatable drum provided with at least one magnetic head, one of said drums having a shaft and an auxiliary member and the other drum having a housing, which shaft is secured to the auxiliary member, the shaft being radially supported and the auxiliary member being axially supported in the housing.
A bearing arrangement of the type defined in the opening paragraph is known from DE 25 37 758 C2. In this prior-art bearing arrangement the shaft is radially supported by means of a spiral-groove bearing and the auxiliary member is constituted by a free shaft end which forms a rigid unit with the shaft and is formed with spiral grooves for the axial support. For a correct bearing construction such an arrangement requires that for the axial support one wall of the shaft end extends perpendicularly to the cylindrical wall of the shaft and that a cylindrical inner wall of the housing extends perpendicularly to a bottom wall of the housing. If these requirements are not met the clearance between the walls forming the axial bearing structure will not be uniform, which may give rise to local contact between the two walls, which is undesirable. As a result of said requirements the costs of manufacturing the prior-art bearing arrangement will be comparatively high and the axial bearing construction will not always be optimum because of the inevitable manufacturing tolerance on the perpendicularity of the walls.